1. Field of the Invention
The present invention is generally related to a fuel system for an internal combustion engine and, more particularly, to a fuel system that incorporates an air compressor that has an air inlet connected to a discharge port of a crank case of the engine to provide a charge of pressurized air at the air inlet of the compressor.
2. Description of the Prior Art
Many different types of internal combustion engine fuel system are known to those skilled in the art. When the internal combustion engine is provided with a direct fuel injection system (DFI), it is well known to provide an air compressor for the purpose of providing pressurized air that is used during the fuel injection procedure.
U.S. Pat. No. 5,456,239, which issued to Henderson on Oct. 10, 1995, describes a crankcase ventilation system for a vehicle which includes an arrangement of flow conduits and control valves which cooperate with a two-chamber accumulator and with various vehicle components to route crankcase gases to the intake manifold. The primary vehicle components include a compressor, an after cooling positioned downstream from the compressor, and an engine having an intake manifold and a crankcase. One chamber of the accumulator is coupled by one conduit to the inlet side of the compressor and by a second conduit to the outlet side of the compressor. These two conduits are controlled by a duel valve arrangement. The other chamber of the accumulator is connected by one conduit to the crankcase and by a separate conduit to the intake manifold. Each conduit includes a control valve. The system operates on pressure differences existing between these various components. The cycle begins by opening the conduit which is connected to the inlet side of the compressor. This creates a low pressure on that side of the diaphragm. Due to their higher pressure, s the crankcase gases empty into the accumulator and when a predetermined pressure is reached, the various valves change state, allowing the higher pressure side of the compressor to empty into the accumulator. This pushes the lower pressure crankcase gases out of the accumulator through a different conduit to the intake manifold. These crankcase gases are then burned in the cylinder and the crankcase gases are not vented directly to the atmosphere.
Air compressors have been used to provide high pressure air to the intake manifold of an internal combustion engine in order to provide a flow of pressurized air into the combustion chambers of the engine. Various types of fuel injected engines use compressors to provide high pressure air which is then controlled by the injectors to cause the high pressure air to flow into the combustion chambers along with a predetermined quantity of fuel. Certain carbureted engines also use pressurized air to provide turbocharging. In typical applications, the air compressor receives an inflow of air from the ambient surroundings. If it is necessary to provide the cylinders of the engine with a higher rate of air flow into the combustion chambers, a typical solution is to use a compressor with a higher volumetric capacity. This, in turn, requires a larger compressor. In many applications, space is at a high premium. For example, internal combustion engines that are used in outboard motor applications have limited space under the cowl. The requirement of a larger compressor is difficult to satisfy because of consideration of space under the cowl.
It would therefore be significantly beneficial if a means could be provided to increase the rate of air flow through a compressor to the combustion chambers of the engine without requiring a larger compressor.